WO2015045450A1 - Resin composition, cured product obtained by curing same, and optical adhesive comprising resin composition - Google Patents

Abstract

A resin composition which comprises a polymer (A) which includes a monomeric unit (a1) derived from a conjugated diene compound and has a polymerizable functional group, a polymer (B) which includes a monomeric unit (b1) derived from a farnesene and does not have a polymerizable functional group, and a polymerization initiator (C), wherein the mass ratio [(A)/(B)] of polymer (A) and polymer (B) is 0.01 to 100.

Description

Resin composition, cured product obtained by curing the same, and optical pressure-sensitive adhesive containing the resin composition

The present invention relates to a resin composition containing a polymer containing a monomer unit derived from farnesene, a cured product obtained by curing the polymer, and an optical pressure-sensitive adhesive containing this resin composition.

In recent years, with the widespread use of electronic devices having a screen such as a liquid crystal, such as smartphones and tablet PCs, research on transparent resin materials and transparent resin adhesives used to cover the screen has been actively conducted.
For example, Patent Document 1 discloses a composition comprising polyisoprene having a (meth) acryloyl group in the molecule, a monofunctional (meth) acrylate monomer and a radical polymerization initiator, and further having a secondary amino group in the molecule. A curable resin composition containing an unhindered amine compound is described.
Patent Document 2 describes a thermosetting resin composition containing an epoxy resin, a curing agent, and an epoxidized polybutadiene having a specific number average molecular weight and an epoxy group in the molecule. .
Patent Documents 3 and 4 describe polymers of β-farnesene, but their practical use has not been sufficiently studied.

Japanese Patent No. 5073400 Japanese Patent No. 4098107 International Publication No. 2010/027463 International Publication No. 2010/027464

The curable resin compositions described in Patent Documents 1 and 2 have room for improvement in terms of viscosity from the viewpoint of improving coatability, and the cured product is required for electronic devices having a screen such as liquid crystal. There was room for improvement in terms of strength, flexibility and transparency.
The present invention has been made in view of the above circumstances, a resin composition capable of giving a cured product having a low viscosity and excellent in strength, flexibility and transparency, a cured product obtained by curing the resin composition, and An optical pressure-sensitive adhesive containing this resin composition is provided.

As a result of intensive studies, the present inventors have found that a polymer having a polymerizable functional group containing a monomer unit derived from a conjugated diene compound and a polymerizable functional group containing a monomer unit derived from farnesene. The present invention was completed by finding that the resin composition containing a polymer not having a specific ratio has a low viscosity and can give a cured product excellent in strength, flexibility, hardness and transparency. .

That is, this invention makes the following a summary.
[1] A polymer (A) containing a monomer unit (a1) derived from a conjugated diene compound and having a polymerizable functional group, a monomer unit (b1) derived from farnesene and having a polymerizable functional group The polymer (B) and the polymerization initiator (C) that are not present are contained, and the mass ratio [(A) / (B)] of the polymer (A) and the polymer (B) is 0.01 to 100. Resin composition.
[2] A cured product obtained by curing the resin composition according to [1].
[3] An optical pressure-sensitive adhesive containing the resin composition according to [1].

ADVANTAGE OF THE INVENTION According to this invention, the viscosity which is low and can give the hardened | cured material which is excellent in intensity | strength, a softness | flexibility, and transparency, the hardened | cured material which hardened this, and the optical adhesive containing this resin composition Can provide.

[Resin composition]
The resin composition of the present invention includes a monomer unit (a1) derived from a conjugated diene compound, a polymer (A) having a polymerizable functional group, a monomer unit (b1) derived from farnesene, and polymerized. It contains a polymer (B) having no possible functional group and a polymerization initiator (C), and the mass ratio [(A) / (B)] of the polymer (A) to the polymer (B) is 0. 01 to 100.

<Polymer (A)>
The polymer (A) includes a monomer unit (a1) derived from a conjugated diene compound and has a polymerizable functional group.
The conjugated diene compound as the monomer unit (a1) is preferably farnesene and a conjugated diene compound having 12 or less carbon atoms. Examples of the conjugated diene compound having 12 or less carbon atoms include butadiene, isoprene, 2,3-dimethylbutadiene, 2-phenylbutadiene, 1,3-pentadiene, 2-methyl-1,3-pentadiene, 1,3-hexadiene, 1,3-octadiene, 1,3-cyclohexadiene, 2-methyl-1,3-octadiene, Examples include 1,3,7-octatriene, myrcene and chloroprene. Of these, farnesene, isoprene and butadiene are more preferred. These conjugated diene compounds may be used individually by 1 type, and may use 2 or more types together.

The monomer unit derived from farnesene may be a monomer unit derived from α-farnesene, or may be a monomer unit derived from β-farnesene represented by the following formula (I). However, from the viewpoint of ease of production, a monomer unit derived from β-farnesene is preferable. Note that α-farnesene and β-farnesene may be used in combination.

Examples of the polymerizable functional group include (meth) acryloyl group, epoxy group, oxetanyl group, vinyl ether group, alkoxysilyl group, (meth) acrylamide group, styrene group, maleimide group, lactone group, lactam group, sulfide group, Examples include a thietane group, an acetonide group, and a thiourea group. Among these, at least one selected from a (meth) acryloyl group, an epoxy group, an oxetanyl group, a vinyl ether group, and an alkoxysilyl group is preferable, and a (meth) acryloyl group is more preferable. These functional groups may have a substituent.
In the present specification, “(meth) acryloyl” means “acryloyl or methacryloyl”. In the present specification, “(meth) acryl” means “acryl or methacryl”.

As a first method for producing the polymer (A) used in the present invention, for example, a functional group that can be polymerized by polymerizing monomers other than the conjugated diene compound and, if necessary, the conjugated diene compound, is used. Examples thereof include a method of preparing an unmodified polymer having no polymer and introducing a polymerizable functional group into the unmodified polymer.
Specifically, an unmodified polymer obtained by living anion polymerization of each of the monomers is reacted with a compound for grafting such as maleic anhydride, and then 2-hydroxyethyl methacrylate or the like. Examples include a method of reacting a compound having a polymerizable functional group.

Examples of the compound for grafting the unmodified polymer include unsaturated carboxylic acid anhydrides such as maleic anhydride, citraconic anhydride, 2,3-dimethylmaleic anhydride and itaconic anhydride; maleic acid and fumaric acid Unsaturated carboxylic acids such as citraconic acid and itaconic acid; unsaturated carboxylic acid esters such as maleic acid ester, fumaric acid ester, citraconic acid ester and itaconic acid ester; maleic acid amide, fumaric acid amide, citraconic acid amide and itaconic acid Unsaturated carboxylic acid amides such as amides; Unsaturated carboxylic acid imides such as maleic imides, fumaric imides, citraconic imides, itaconic imides; maleimides, vinyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, etc. It is done.
Examples of the compound having a polymerizable functional group include (meth) acrylic acid; 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, pentaerythritol triacrylate, pentaerythritol trimethacrylate, (Meth) acrylates such as pentaerythritol monohydroxyacrylate; 2-hydroxyethyl vinyl ether, N- (2-hydroxyethyl) acrylamide, N- (2-hydroxyethyl) methacrylamide, N- (2-hydroxyethyl) maleimide, 4 -Ethenylphenol and the like. The position at which the polymerizable functional group is introduced may be the polymerization terminal or the side chain of the polymer. Moreover, the said functional group may combine 1 type (s) or 2 or more types.

As a second method for producing the polymer (A) used in the present invention, for example, a hydroxyl group with respect to the living terminal of an unmodified polymer obtained by subjecting the conjugated diene compound to living anion polymerization by the method described below, Carboxyl group, carbonyl group, thiocarbonyl group, acid halide group, acid anhydride group, thiocarboxylic acid group, aldehyde group, thioaldehyde group, carboxylic acid ester group, amide group, sulfonic acid group, sulfonic acid ester group, phosphoric acid Group, phosphate ester group, amino group, imino group, nitrile group, pyridyl group, quinoline group, epoxy group, thioepoxy group, sulfide group, isocyanate group, isothiocyanate group, silanol group, alkoxysilane, silicon halide group, halogen Government selected from tin oxide group, alkoxytin group, phenyltin group, etc. Groups by addition reaction of a compound having at least one, then, a method of reacting a compound having a polymerizable functional group.

Living anionic polymerization initiators for living anion polymerization of the conjugated diene compound include, for example, methyl lithium, ethyl lithium, n-butyl lithium, sec-butyl lithium, t-butyl lithium, hexyl lithium, phenyl lithium, stilbene lithium and the like. Organic monolithium compounds such as: dilithiomethane, dilithionaphthalene, 1,4-dilithiobutane, 1,4-dilithio-2-ethylcyclohexane, 1,3,5-trilithiobenzene, and the like; sodium naphthalene, Examples include potassium naphthalene. Moreover, you may use together compounds, such as diisopropenyl benzene and dibenzyl toluene which react with an organic alkali metal compound and give a polyfunctional organic alkali metal compound.
Examples of the compound having at least one functional group that undergoes addition reaction with respect to the living terminal include cyclic ethers such as epoxide and oxetane; cyclic amines such as pyrrolidine; cyclic sulfides such as ethylene sulfide.

As a third method for producing the polymer (A) used in the present invention, an unmodified polymer is obtained by polymerizing a conjugated diene compound and, if necessary, a monomer other than the conjugated diene compound by the method described below. There is a method of preparing and epoxidizing this unmodified polymer and then reacting a compound having a polymerizable functional group. Examples of the compound for epoxidizing the unmodified polymer include peracids such as peracetic acid and perbenzoic acid.

Examples of the compound having a polymerizable functional group in these methods include carboxylic acids such as acrylic acid and methacrylic acid. The position at which the polymerizable functional group is introduced may be the polymerization terminal or the side chain of the polymer. Moreover, the compound which has the said polymerizable functional group may combine 1 type (s) or 2 or more types.

When functionalizing the unmodified polymer or storing the modified polymer, an antiaging agent suitable for the unmodified polymer or the modified polymer is used for the purpose of suppressing molecular weight reduction, discoloration and gelation due to deterioration. You may combine. Specifically, 2,6-di-t-butyl-4-methylphenol (BHT), 2,2′-methylenebis (4-methyl-6-t-butylphenol), 4,4′-thiobis (3-methyl) -6-tert-butylphenol), 4,4'-butylidenebis (3-methyl-6-tert-butylphenol) (AO-40), 3,9-bis [1,1-dimethyl-2- [3- (3 -T-butyl-4-hydroxy-5-methylphenyl) propionyloxy] ethyl] -2,4,8,10-tetraoxaspiro [5.5] undecane (AO-80), 2,4-bis [( Octylthio) methyl] -6-methylphenol (Irganox 1520L), 2,4-bis [(dodecylthio) methyl] -6-methylphenol (Irganox 1726), 2- [1- (2-hydroxy-3,5-di t-pentylphenyl) ethyl] -4,6-di-t-pentylphenyl acrylate (Sumilizer GS), 2-t-butyl-6- (3-t-butyl-2-hydroxy-5-methylbenzyl) -4- Methylphenyl acrylate (Sumilizer GM), 6-t-butyl-4- [3- (2,4,8,10-tetra-t-butyldibenzo [d, f] [1,3,2] dioxaphosphine Pin-6-yloxy) propyl] -2-methylphenol (Sumilizer GP), tris (2,4-di-t-butylphenyl) phosphite (Irgafos 168), dioctadecyl 3,3′-dithiobispropionate , Hydroquinone, p-methoxyphenol, N-phenyl-N ′-(1,3-dimethylbutyl) -p-phenylenediamine (NOCRACK 6C), (2,2,6,6-tetramethyl-4-piperidyl) sebacate (LA-77Y), N, N-dioctadecylhydroxylamine (Irgastab FS 042), bis (4-t-octylphenyl) amine (Irganox 5057) ) And the like. Moreover, the said anti-aging agent may be used individually by 1 type, and may use 2 or more types together.
The addition amount of the antioxidant is preferably 0.01 to 10 parts by mass, more preferably 0.1 to 3 parts by mass with respect to 100 parts by mass of the unmodified polymer or modified polymer.

The monomer unit constituting the polymer (A) may consist only of the monomer unit (a1) derived from the conjugated diene compound, and the monomer unit (a1) and conjugated diene derived from the conjugated diene compound. It may consist of a monomer unit (a2) derived from a monomer other than the compound. That is, the unmodified polymer may be obtained by polymerizing only the conjugated diene compound, or may be a copolymer of the conjugated diene compound and a monomer other than the conjugated diene compound.

When the unmodified polymer is a copolymer, examples of the monomer unit (a2) derived from a monomer other than the conjugated diene compound include monomer units derived from an aromatic vinyl compound.
Examples of the aromatic vinyl compound include styrene, α-methyl styrene, 2-methyl styrene, 3-methyl styrene, 4-methyl styrene, 4-propyl styrene, 4-tert-butyl styrene, 4-cyclohexyl styrene, 4-dodecyl. Styrene, 2,4-dimethylstyrene, 2,4-diisopropylstyrene, 2,4,6-trimethylstyrene, 2-ethyl-4-benzylstyrene, 4- (phenylbutyl) styrene, 1-vinylnaphthalene, 2-vinyl Naphthalene, vinyl anthracene, N, N-diethyl-4-aminoethylstyrene, vinylpyridine, 4-methoxystyrene, monochlorostyrene, dichlorostyrene, divinylbenzene and the like can be mentioned. Of these, styrene, α-methylstyrene, and 4-methylstyrene are preferable.

When the monomer unit (a2) derived from a monomer other than the conjugated diene compound is used, the monomer unit (a1) derived from the conjugated diene compound in the copolymer and the monomer other than the conjugated diene compound The ratio of the monomer unit (a2) derived from the monomer other than the conjugated diene compound relative to the total amount of the monomer units (a2) derived is from the viewpoint of reducing the viscosity of the resin composition, and good elongation of the cured film. From the viewpoint of maintaining characteristics and flexibility, it is preferably 1 to 99% by mass, more preferably 1 to 80% by mass, still more preferably 1 to 70% by mass, and even more preferably 1 to 50% by mass.

The number average molecular weight (Mn) of the polymer (A) used in the present invention is preferably 1,000 to 1,000,000, more preferably 2,000 to 500,000, more preferably 8,000 to 500,000, and 15,000. To 450,000 are more preferable, 15,000 to 300,000 are more preferable, and 20,000 to 200,000 are more preferable. When the Mn of the polymer (A) is within the above range, the flexibility and mechanical strength of the cured product are improved and the resin composition has a low viscosity.
In addition, the number average molecular weight (Mn) in this specification is a number average molecular weight in terms of polystyrene measured by gel permeation chromatography (GPC).

The melt viscosity at 38 ° C. of the polymer (A) used in the present invention is preferably 0.1 to 3,000 Pa · s, more preferably 0.2 to 3,000 Pa · s, and more preferably 0.2 to 2,800 Pa · s. s is more preferable, and 0.3 to 2,600 Pa · s is still more preferable. When the melt viscosity of the polymer (A) is within the above range, the resin composition can be uniformly applied to the surface to be coated, so that the coating property is improved.
In the present specification, the melt viscosity of the polymer is a value determined by the method described in the examples described later.

The number of polymerizable functional groups per molecular chain of the polymer (A) used in the present invention is preferably 1 to 150, more preferably 1.5 to 75, still more preferably 1.5 to 30. When the number of polymerizable functional groups per molecular chain is within the above range, the viscosity of the polymer (A) can be reduced, the curing speed can be improved, and the shrinkage during curing can be further improved. Can be kept low.
The number of polymerizable functional groups per molecular chain is expressed by the following formula from the number average molecular weight (Mn) of the polymer (A) and the functional group equivalent (g / eq) of the polymer (A). Calculated.
(Number of polymerizable functional groups per molecular chain) = (Mn) / (functional group equivalent)
The functional group equivalent is an amount representing “molecular weight of polymer per functional group”. For example, the functional group equivalent when the polymerizable functional group is a methacryloyl group is referred to as “methacryloyl equivalent”, which means “molecular weight of polymer per methacryloyl group”. The functional group equivalent can be calculated based on the reaction rate of the modifier, or can be determined using various analytical instruments such as infrared spectroscopy and nuclear magnetic resonance spectroscopy.

The polymer (A) used in the present invention may be used alone, but two or more kinds of the polymers (A) having different monomer units, molecular weights and functional groups are mixed. It may be used.

The content of the polymer (A) in the total amount of the resin composition is preferably 1 to 99% by mass, more preferably 2 to 98% by mass, further preferably 5 to 95% by mass, and still more preferably 10 to 90% by mass. Preferably, 15 to 85% by mass is even more preferable. When the content of the polymer (A) in the resin composition is within the above range, a cured product having excellent strength, flexibility, and transparency can be provided.

<Polymer (B)>
The polymer (B) is a polymer containing a farnesene-derived monomer unit (b1) and having no polymerizable functional group. As this farnesene, the same thing as what was demonstrated by the above-mentioned polymer (A) can be used. The monomer unit constituting the polymer (B) may be composed only of the farnesene-derived monomer unit (b1), or derived from a monomer other than the farnesene-derived monomer unit (b1) and farnesene. It may consist of the monomer unit (b2).

Examples of the monomer unit (b2) derived from monomers other than farnesene include monomer units derived from conjugated diene compounds and aromatic vinyl compounds.
The conjugated diene compound is preferably a conjugated diene compound having 12 or less carbon atoms. Examples of the conjugated diene compound having 12 or less carbon atoms include butadiene, isoprene, 2,3-dimethylbutadiene, 2-phenylbutadiene, 1,3-pentadiene, 2-methyl-1,3-pentadiene, 1,3-hexadiene, 1,3-octadiene, 1,3-cyclohexadiene, 2-methyl-1,3-octadiene, 1,3,7-octatriene, myrcene, Examples include chloroprene. Of these, isoprene and butadiene are more preferred. These conjugated diene compounds may be used individually by 1 type, and may use 2 or more types together.

Examples of the aromatic vinyl compound include styrene, α-methyl styrene, 2-methyl styrene, 3-methyl styrene, 4-methyl styrene, 4-propyl styrene, 4-tert-butyl styrene, 4-cyclohexyl styrene, 4-dodecyl. Styrene, 2,4-dimethylstyrene, 2,4-diisopropylstyrene, 2,4,6-trimethylstyrene, 2-ethyl-4-benzylstyrene, 4- (phenylbutyl) styrene, 1-vinylnaphthalene, 2-vinyl And aromatic vinyl compounds such as naphthalene, vinylanthracene, N, N-diethyl-4-aminoethylstyrene, vinylpyridine, 4-methoxystyrene, monochlorostyrene, dichlorostyrene, and divinylbenzene. Of these, styrene, α-methylstyrene, and 4-methylstyrene are preferable.

In the case of using a monomer unit (b2) derived from a monomer other than farnesene, the monomer unit derived from a monomer other than farnesene (b1) and a monomer other than farnesene in the copolymer The ratio of the monomer unit (b2) derived from the monomer other than farnesene to the total of (b2) is the viewpoint of reducing the viscosity of the resin composition, the viewpoint of improving the curing rate, and the good elongation characteristics of the cured film. From the viewpoint of maintaining flexibility, it is preferably 1 to 99% by mass, more preferably 1 to 80% by mass, still more preferably 1 to 70% by mass, and still more preferably 1 to 50% by mass.

The number average molecular weight (Mn) of the polymer (B) used in the present invention is preferably 1,000 to 1,000,000, more preferably 1,000 to 500,000, more preferably 1,000 to 200,000, and 5,000. ˜200,000 is more preferred, and 5,000 to 150,000 is even more preferred. When the Mn of the polymer (B) is within the above range, the flexibility and mechanical strength of the cured product are improved, and the resin composition has a low viscosity.

The melt viscosity at 38 ° C. of the polymer (B) used in the present invention is preferably 0.1 to 3,000 Pa · s, more preferably 0.2 to 3,000 Pa · s, and more preferably 0.2 to 2,800 Pa · s. s is more preferable, and 0.3 to 2,600 Pa · s is still more preferable. When the melt viscosity of the polymer (B) is within the above range, the resin composition can be uniformly applied to the surface to be coated without unevenness, so that the coating property is improved.

The molecular weight distribution (Mw / Mn) of the polymer (B) used in the present invention is preferably 1.0 to 8.0, more preferably 1.0 to 5.0, and still more preferably 1.0 to 3.0. . When Mw / Mn is within the above range, variation in the viscosity of the resulting polymer (B) is reduced.

The glass transition temperature of the polymer (B) used in the present invention varies depending on the bonding mode (microstructure), farnesene-derived monomers, and the amount of monomers other than farnesene used as necessary. A range of −90 to 0 ° C. is preferable, and a range of −90 to −10 ° C. is more preferable. Within the above range, a flexible cured product can be obtained, and in the optical pressure-sensitive adhesive that is one of the uses of the present invention, the step following property and the impact absorbing property are improved.

The polymer (B) used in the present invention may be used alone, or two or more kinds of the polymers (B) having different monomer units and molecular weights may be mixed and used. The polymer (B) used in the present invention can be produced by an emulsion polymerization method, a method described in International Publication No. 2010/027463, International Publication No. 2010/027464, or the like. Among these, an emulsion polymerization method or a solution polymerization method is preferable, and a solution polymerization method is more preferable.

(Emulsion polymerization method)
As an emulsion polymerization method for obtaining the polymer (B), a known method can be applied. For example, a predetermined amount of farnesene monomer is emulsified and dispersed in the presence of an emulsifier, and emulsion polymerization is performed using a radical polymerization initiator.
As the emulsifier, for example, a long chain fatty acid salt or rosin acid salt having 10 or more carbon atoms is used. Specific examples include potassium salts or sodium salts of fatty acids such as capric acid, lauric acid, myristic acid, palmitic acid, oleic acid and stearic acid.
As the dispersant, water is usually used, and it may contain a water-soluble organic solvent such as methanol and ethanol as long as the stability during polymerization is not inhibited.
Examples of the radical polymerization initiator include persulfates such as ammonium persulfate and potassium persulfate, organic peroxides, and hydrogen peroxide.
Chain transfer agents can also be used to adjust the molecular weight of the polymer. Examples of the chain transfer agent include mercaptans such as t-dodecyl mercaptan and n-dodecyl mercaptan; carbon tetrachloride, thioglycolic acid, diterpene, terpinolene, γ-terpinene, α-methylstyrene dimer and the like.
The emulsion polymerization temperature can be appropriately selected depending on the type of radical polymerization initiator to be used, but is usually preferably 0 to 100 ° C, more preferably 0 to 60 ° C. The polymerization mode may be either continuous polymerization or batch polymerization. The polymerization reaction can be stopped by adding a polymerization terminator.
Examples of the polymerization terminator include amine compounds such as isopropylhydroxylamine, diethylhydroxylamine, and hydroxylamine, quinone compounds such as hydroquinone and benzoquinone, and sodium nitrite.
After termination of the polymerization reaction, an antioxidant may be added as necessary. After the polymerization reaction is stopped, unreacted monomers are removed from the obtained latex as necessary, and then a salt such as sodium chloride, calcium chloride, potassium chloride is used as a coagulant, and nitric acid, sulfuric acid, etc. The polymer is recovered by coagulating the polymer while adjusting the pH of the coagulation system to a predetermined value by adding an acid, and then separating the dispersion solvent. Subsequently, a polymer is obtained by drying after water washing and dehydration. In addition, at the time of coagulation, if necessary, latex and an extending oil that has been made into an emulsified dispersion may be mixed and recovered as an oil-extended polymer.

(Solution polymerization method)
As a solution polymerization method for obtaining a polymer, a known method can be applied. For example, the farnesene monomer is polymerized in the presence of a polar compound as desired using a Ziegler catalyst, a metallocene catalyst, or an anionically polymerizable active metal in a solvent.
Examples of the active metal capable of anion polymerization include alkali metals such as lithium, sodium and potassium; alkaline earth metals such as beryllium, magnesium, calcium, strontium and barium; lanthanoid rare earth metals such as lanthanum and neodymium. Of these, alkali metals and alkaline earth metals are preferable, and alkali metals are particularly preferable. Furthermore, an organic alkali metal compound is more preferably used.
Examples of the solvent include aliphatic hydrocarbons such as n-butane, n-pentane, isopentane, n-hexane, n-heptane and isooctane; alicyclic hydrocarbons such as cyclopentane, cyclohexane and methylcyclopentane; benzene, toluene And aromatic hydrocarbons such as xylene.
Examples of the organic alkali metal compound include organic monolithium compounds such as methyl lithium, ethyl lithium, n-butyl lithium, sec-butyl lithium, t-butyl lithium, hexyl lithium, phenyl lithium and stilbene lithium; dilithiomethane, dilithionaphthalene, Polyfunctional organolithium compounds such as 1,4-dilithiobutane, 1,4-dilithio-2-ethylcyclohexane, 1,3,5-trilithiobenzene; sodium naphthalene, potassium naphthalene and the like. Among these, an organic lithium compound is preferable, and an organic monolithium compound is more preferable. The amount of the organic alkali metal compound to be used is appropriately determined depending on the required molecular weight of the polymer, but is 0.01 to 7 parts by mass with respect to 100 parts by mass of the total amount of monomers other than farnesene and farnesene as required. preferable.
The organic alkali metal compound can also be used as an organic alkali metal amide by reacting with a secondary amine such as dibutylamine, dihexylamine, dibenzylamine and the like.
The polar compound is used to adjust the microstructure of the farnesene site without deactivating the reaction in anionic polymerization. For example, ether compounds such as dibutyl ether, tetrahydrofuran, and ethylene glycol diethyl ether; tetramethylethylenediamine, trimethylamine, and the like 3 Secondary amines; alkali metal alkoxides, phosphine compounds, and the like. The polar compound is preferably used in an amount of 0.01 to 1000 molar equivalents relative to the organic alkali metal compound.

The temperature of the polymerization reaction is usually in the range of −80 to 150 ° C., preferably 0 to 100 ° C., more preferably 10 to 90 ° C. The polymerization mode may be either batch or continuous.
The polymerization reaction can be stopped by adding an alcohol such as methanol or isopropanol as a polymerization terminator. The polymer can be isolated by pouring the obtained polymerization reaction liquid into a poor solvent such as methanol to precipitate the polymer, or washing the polymerization reaction liquid with water, separating, and drying.

In the present invention, the mass ratio [(A) / (B)] of the polymer (A) and the polymer (B) is 0.01 to 100, preferably 0.05 to 100, more preferably. It is 0.1 to 50, more preferably 0.1 to 25, and still more preferably 0.1 to 10. When the mass ratio (A) / (B) is within the above range, a resin composition having a sufficiently low viscosity and a good elongation at break after curing can be obtained.

In the present invention, at least one of the polymer (A) and the polymer (B) preferably has a melt viscosity at 38 ° C. of 0.1 to 3,000 Pa · s, but the polymer (A) and the polymer More preferably, the melt viscosity of both (B) is in the range of 0.1 to 3,000 Pa · s.

<Polymerization initiator (C)>
Examples of the polymerization initiator (C) used in the present invention include a photopolymerization initiator that initiates a polymerization reaction by irradiation with active energy rays such as ultraviolet rays, and a thermal polymerization initiator that initiates a polymerization reaction by heat. Among these, a photopolymerization initiator is preferred from the viewpoint that the resin is cured by short-time irradiation and a cured product can be obtained without deteriorating the base material, and photopolymerization initiation in which a polymerization reaction is initiated by ultraviolet irradiation. An agent is more preferable. Examples of the photopolymerization initiator include a cationic photopolymerization initiator and a radical polymerization initiator.

Examples of the cationic photopolymerization initiator include aromatic diazonium salts, aromatic iodonium salts, aromatic sulfonium salts, metallocene compounds, and the like.
As a cationic photopolymerization initiator of an aromatic diazonium salt, “P-33 (trade name)” (manufactured by ADEKA Corporation) and the like are known.
Known examples of cationic photopolymerization initiators of aromatic iodonium salts include “Rhodorsil Photo Initiator 2074 (trade name)” (manufactured by Rhodia Co., Ltd.), “Irgacure 250 (trade name)” (manufactured by BASF Corporation), and the like. Yes.
As the cationic photopolymerization initiator of aromatic sulfonium salt, “FC-509 (trade name)” (manufactured by Sumitomo 3M Limited), “Irgacure 270 (trade name)” (manufactured by BASF Corporation) and the like are known. Yes.
As a metallocene-based cationic photopolymerization initiator, “Irgacure 261 (trade name)” (manufactured by BASF Corporation) and the like are known.
Examples of radical photopolymerization initiators include acetophenone, benzophenone, alkylphenone, acylphosphine oxide, benzoin, ketal, anthraquinone, disulfide, thioxanthone, thiuram, and fluoroamine. . Of these, alkylphenone-based or acylphosphine oxide-based radical photopolymerization initiators are preferred.
Examples of the alkylphenone radical photopolymerization initiators include hydroxyalkylphenone and aminoalkylphenone. Hydroxylphenone radical photopolymerization initiators include “DAROCUR 1173 (trade name)” (2-hydroxy-2-methyl-1-phenylpropan-1-one), “Irgacure 184 (trade name)” (1 -Hydroxycyclohexyl phenyl ketone), “Irgacure 2959 (trade name)” (1- [4- (2-hydroxyethoxy) -phenyl] -2-hydroxy-2-methyl-1-propan-1-one) and the like It is done.
Examples of aminoalkylphenone radical photopolymerization initiators include “Irgacure 907 (trade name)” (2-methyl-1- (4-methylthiophenyl) -2-morpholinopropan-1-one), “Irgacure 369”. (Trade name) ”(2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -1-butanone) and the like.
Acylphosphine oxide radical photopolymerization initiators include “LUCIRIN TPO (trade name)” (2,4,6-trimethylbenzoyldiphenylphosphine oxide), “Irgacure 819 (trade name)” (bis (2,4 , 6-trimethylbenzoyl) -phenylphosphine oxide) (all manufactured by BASF Corporation).
Among these, hydroxyalkylphenone-based radical photopolymerization initiators are preferable, and 2-hydroxy-2-methyl-1-phenylpropan-1-one is more preferable. These may be used alone or in combination of two or more.

The content of the polymerization initiator (C) in the total amount of the resin composition is preferably 0.1 to 20% by mass, more preferably 0.5 to 20% by mass, still more preferably 1.0 to 20% by mass, 1.0 to 15% by mass is even more preferable, and 1.0 to 10% by mass is most preferable. When the content of the polymerization initiator (C) is within the above range, it is preferable in terms of curing speed and mechanical properties.

<Monomer (D)>
The resin composition of the present invention may contain a monomer (D) as necessary in order to further improve the viscosity, handleability and strength after curing of the resin composition. The monomer (D) preferably has a functional group capable of reacting with the polymer (A). For example, a compound having (meth) acryloyl group, epoxy group, oxetanyl group, vinyl ether group, alkoxysilyl group in the molecule. Is mentioned.

Specific compounds include, for example, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, butylethoxy (meth) acrylate, butylethyl (meth) acrylate, 2-ethylhexyl (meth) ) Acrylate, lauryl (meth) acrylate, dicyclopentenyl (meth) acrylate, dicyclopentenyloxyethyl (meth) acrylate, dicyclopentanyl (meth) acrylate, dicyclopentanyloxyethyl (meth) acrylate, cyclohexyl (meth) ) Acrylate, isobornyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, phenoxyhydroxypropyl (meth) acrylate Rate, morpholine (meth) acrylate, phenoxyethyl (meth) acrylate, N, N-diethylaminoethyl (meth) acrylate, N, N-dimethylaminoethyl (meth) acrylate, glycidyl (meth) acrylate, methoxydiethylene glycol (meth) Monofunctional (meth) acrylates such as acrylate, methoxydipropylene glycol (meth) acrylate, nonylphenoxypolyethylene glycol (meth) acrylate;

1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, 1,9-nonanediol di (meth) acrylate, dimethylol tricyclodecane di (meth) acrylate, ethylene glycol di Bifunctional (meth) acrylates such as (meth) acrylate, glycerin di (meth) acrylate, ethylene oxide modified bisphenol A di (meth) acrylate, triethylene glycol di (meth) acrylate;
Trimethylolpropane tri (meth) acrylate, ethylene oxide modified trimethylolpropane tri (meth) acrylate, ditrimethylolpropane tetra (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol hexa Polyfunctional (meth) acrylates such as (meth) acrylate and ditrimethylolpropane tetra (meth) acrylate;
3,4-epoxycyclohexenylmethyl-3 ′, 4′-epoxycyclohexene carboxylate, 1,2-epoxy-4-vinylcyclohexane, 1,2: 8,9-diepoxy limonene, 2,6,6 An epoxy compound such as trimethyl-2,3-epoxybicyclo [3.1.1] heptane;

3-ethyl-3-hydroxymethyloxetane, 1,4-bis [(3-ethyl-3-oxtanylmethoxy) methyl] benzene, 3-ethyl-3- (phenoxymethyl) oxetane, bis [1-ethyl (3 -Oxetanyl)] methyl ether, oxetane compounds such as 3-ethyl-3- (2-ethylhexyloxymethyl) oxetane;
Vinyl ether compounds such as 2-hydroxyethyl vinyl ether, 4-hydroxybutyl vinyl ether, diethylene glycol monovinyl ether;
Examples thereof include silane compounds such as mercaptomethyltrimethoxysilane, glycidoxymethyltrimethoxysilane, and vinylmethyltrimethoxysilane.
Among them, the monomer (D) is at least selected from monofunctional (meth) acrylate, bifunctional (meth) acrylate and polyfunctional (meth) acrylate from the viewpoint of good compatibility with the polymer (A). It is preferable that it is 1 type, and it is more preferable that it is at least 1 type chosen from monofunctional (meth) acrylate and bifunctional (meth) acrylate. Among them, dicyclopentenyloxyethyl (meth) acrylate, 1,9-nonanediol di (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, dicyclopentenyl (meth) acrylate, phenoxyethyl (meth) ) Acrylate and the like are particularly preferable. These may be used alone or in combination of two or more.

The monomer (D) can react with the polymerizable functional group of the polymer (A) with a polymerization initiator such as a radical polymerization initiator, a cationic polymerization initiator, and an anionic polymerization initiator. The content of the monomer (D) is preferably 0.01 to 1,000 parts by mass, and 0.1 to 800 parts by mass with respect to 100 parts by mass in total of the polymer (A) and the polymer (B). Part is more preferred, 1.0 to 600 parts by weight is still more preferred, and 1.0 to 400 parts by weight is even more preferred. When the content of the monomer (D) is within the above range, the viscosity is lowered and handling properties are improved. Moreover, since the breaking strength and tensile elongation of a cured film are improved when the resin composition of the present invention is cured, a cured product having excellent flexibility can be obtained.

<Hindered amine compound (E)>
The resin composition of the present invention may contain a hindered amine compound (E) in the molecule as necessary in order to further improve the heat resistance and weather resistance of the resin composition and the cured product obtained therefrom. Good. In addition, as a hindered amine type compound (E), it is preferable to use the hindered amine type compound which does not have a secondary amino group in a molecule | numerator. By using the hindered amine compound (E) having no secondary amino group in the molecule, the physical properties of the resin composition and the cured product obtained therefrom are deteriorated and the color tone is changed after being exposed to heat. Can be remarkably improved.
Examples of such hindered amine compounds (E) having no secondary amino group in the molecule include bis (1,2,2,6,6-pentamethyl-4-piperidyl) sebacate and bis (2,2 , 6,6-tetramethyl-4-piperidyl) sebacate, bis (1,2,2,6,6-pentamethyl-4-piperidyl) {[3,5-bis (1,1-dimethylethyl) -4- Hydroxyphenyl] methyl} butyl malonate, bis (2,2,6,6-tetramethyl-1- (octyloxy) -4-piperidinyl) ester of decanedioic acid, methyl 1,2,2,6,6-pentamethyl -4-piperidyl sebacate, 1,2,3,4-butanetetracarboxylic acid tetrakis (1,2,2,6,6-pentamethyl-4-piperidinyl), 1,2,2,6,6-penta Chill 4-piperidyl methacrylate and the like.
Among them, bis (1,2,2,6,6-pentamethyl-4-piperidyl) sebacate, methyl 1,2,2,6,6-pentamethyl-4-piperidyl sebacate, 1,2,3,4-butane Tetracarboxylic acid tetrakis (1,2,2,6,6-pentamethyl-4-piperidinyl) and the like are preferable. These may be used alone or in combination of two or more.

The content of the hindered amine compound (E) in the total amount of the resin composition is preferably 0.01 to 10% by mass, more preferably 0.5 to 7% by mass, and still more preferably 1 to 4% by mass. When the content of the hindered amine compound (E) is within the above range, it is preferable in terms of improving the heat resistance and improving the mechanical properties of the cured product.

The resin composition of the present invention has a polymerizable functional group obtained by polymerizing a conjugated diene compound other than farnesene, in addition to the polymer (A) and the polymer (B), as long as the effects of the present invention are not impaired. You may contain the conjugated diene polymer which does not have. Conjugated diene compounds other than farnesene include butadiene, isoprene, 2,3-dimethylbutadiene, 2-phenylbutadiene, 1,3-pentadiene, 2-methyl-1,3-pentadiene, 1,3-hexadiene, 1,3 -Octadiene, 1,3-cyclohexadiene, 2-methyl-1,3-octadiene, 1,3,7-octatriene, myrcene, chloroprene and the like.

The resin composition of the present invention is a copolymer of a conjugated diene compound other than farnesene and an aromatic vinyl compound, in addition to the polymer (A) and the polymer (B), within a range that does not impair the effects of the present invention. A conjugated diene compound-aromatic vinyl compound copolymer having no polymerizable functional group obtained in this manner may be contained. Examples of the conjugated diene compound are the same as those described above.
Examples of the aromatic vinyl compound include styrene, α-methyl styrene, 2-methyl styrene, 3-methyl styrene, 4-methyl styrene, 4-propyl styrene, 4-tert-butyl styrene, 4-cyclohexyl styrene, 4-dodecyl. Styrene, 2,4-dimethylstyrene, 2,4-diisopropylstyrene, 2,4,6-trimethylstyrene, 2-ethyl-4-benzylstyrene, 4- (phenylbutyl) styrene, 1-vinylnaphthalene, 2-vinyl Naphthalene, vinyl anthracene, N, N-diethyl-4-aminoethylstyrene, vinylpyridine, 4-methoxystyrene, monochlorostyrene, dichlorostyrene, divinylbenzene and the like can be mentioned.

The contents of the conjugated diene polymer and conjugated diene compound-aromatic vinyl compound copolymer that may be contained in addition to the polymer (A) and the polymer (B) are not particularly limited. However, in a resin composition, 50 mass% or less is preferable, 30 mass% or less is more preferable, and 10 mass% or less is still more preferable.

<Method for producing resin composition>
The method for producing the resin composition of the present invention is not particularly limited. For example, the polymer (A), the polymer (B), the polymerization initiator (C), and other used as necessary. The components can be produced by mixing them at room temperature using ordinary mixing means such as a stirrer or a kneader.

<Melt viscosity of resin composition>
The resin composition of the present invention has a melt viscosity at 38 ° C. of preferably 15 Pa · s or less, more preferably 12 2 Pa · s or less, and still more preferably 10 Pa · s or less. When the melt viscosity of the resin composition is within the above range, it is possible to uniformly apply the resin composition to the surface to be coated, and it is easy to prevent air bubbles from being mixed. Become. In the present specification, the melt viscosity of the resin composition is a value determined by the method described in Examples described later.

Since the resin composition of the present invention has a low melt viscosity, excellent curability, and further a cured product having excellent strength, flexibility and transparency, an adhesive, a pressure-sensitive adhesive (particularly an optical pressure-sensitive adhesive), It can use suitably for uses, such as a coating agent, a sealing material, and ink.

[Cured product]
The cured product of the present invention is obtained by curing the resin composition of the present invention. For example, the polymer (A) can be obtained by irradiating energy rays or applying heat to the resin composition of the present invention. And it can be made to harden | cure by making a polymerization initiator (C) react.
As energy rays for curing, ultraviolet rays are preferable. Examples of the ultraviolet light source include a xenon lamp, a low-pressure mercury lamp, a high-pressure mercury lamp, a metal halide lamp, and a microwave excimer lamp. As an atmosphere for irradiating ultraviolet rays, an inert gas atmosphere such as nitrogen gas or carbon dioxide gas or an atmosphere in which the oxygen concentration is lowered is preferable.
The irradiation atmosphere temperature is preferably 10 to 200 ° C., and the UV irradiation amount is preferably 200 to 10,000 mJ / cm ² .

[Optical pressure sensitive adhesive]
The optical pressure-sensitive adhesive of the present invention contains the resin composition of the present invention, and can be suitably used for electronic devices such as smartphones, liquid crystal displays, and organic EL displays.

In the optical pressure-sensitive adhesive, various additives can be appropriately added as necessary without departing from the object of the present invention. Examples of the additive include a tackifier, a plasticizer, a pigment, a colorant, an anti-aging agent, and an ultraviolet absorber.

EXAMPLES Hereinafter, although an Example demonstrates this invention in detail, this invention is not limited to these Examples.
Each component used in the examples and comparative examples is as follows.
<Polymer (A)>
-Polymers (A-1) and (A-2) obtained by Production Examples 1 and 2 described later

<Polymer (B)>
-Polymers (B-1) and (B-2) obtained by Production Examples 3 and 4 described later
<Polymerization initiator (C)>
・ Polymerization initiator (C-1)
2-hydroxy-2-methyl-1-phenylpropan-1-one manufactured by BASF Corporation, trade name “DAROCUR 1173”
<Monomer (D)>
・ Dicyclopentenyloxyethyl methacrylate, manufactured by Hitachi Chemical Co., Ltd., trade name “Fancryl FA-512M”
<Hindered amine compound (E)>
・ Hindered amine compounds (E-1)
A mixture of bis (1,2,2,6,6-pentamethyl-4-piperidyl) sebacate and methyl 1,2,2,6,6-pentamethyl-4-piperidyl sebacate, manufactured by BASF Corporation, trade name “ TINUVIN 765 "

<Other polymer (X)>
.Polymers (X-1) to (X-3)
Polymers (X-1), (X-2) and (X-3) obtained by Production Examples 5 to 7 described later

<Production Examples 1 to 7>
Production Example 1: Production of polyisoprene (A-1) having a methacryloyl group in the molecule By subjecting isoprene to anionic polymerization in n-hexane using n-butyllithium as an initiator, a polyisoprene having a number average molecular weight of 36,000 is produced. Isoprene was obtained. By adding 1.5 parts by mass of maleic anhydride to 100 parts by mass of this polyisoprene and reacting at 180 ° C. for 15 hours, polyisoprene having 3 acid anhydride groups as an average per molecule was obtained. Next, 2.0 parts by mass of 2-hydroxyethyl methacrylate is added to 100 parts by mass of polyisoprene having three acid anhydride groups as an average per molecule, and the mixture is allowed to react at 120 ° C. for 10 hours after being shielded from light. A modified liquid polyisoprene having three methacryloyl groups as an average per molecule (hereinafter also referred to as “polymer (A-1)”) was obtained. Table 1 shows the physical properties of the polymer (A-1).

Production Example 2: Production of polyfarnesene (A-2) having a methacryloyl group in the molecule In a 5 liter autoclave subjected to nitrogen substitution, 1520 g of cyclohexane and 10.5 mass% cyclohexane solution of sec-butyllithium 7. After charging 8 g, the temperature was raised to 50 ° C., 1510 g of β-farnesene was added, and polymerization was carried out for 2 hours. The obtained polymerization solution was poured into methanol to reprecipitate the unmodified polymer, and was filtered off, followed by vacuum drying at 80 ° C. for 10 hours to obtain 1200 g of polyfarnesene (unmodified polymer).
100 parts by mass of polyfarnesene obtained in an autoclave with a capacity of 1 liter subjected to nitrogen substitution was charged, and 1.5 parts by mass of maleic anhydride and BHT (2,6-di-tert-butyl-4-methylphenol, Honshu Chemical) 1 part by mass) (manufactured by Kogyo Co., Ltd.) was added and reacted at 160 ° C. for 20 hours to obtain polyfarnesene having 11 acid anhydride groups as an average per molecule. Next, 2.0 parts by mass of 2-hydroxyethyl methacrylate is added to 100 parts by mass of this polyfarnesene, light-shielded, and then reacted at 80 ° C. for 6 hours, whereby a modified liquid having 11 methacryloyl groups as an average per molecule is obtained. Polyfarnesene (hereinafter also referred to as “polymer (A-2)”) was obtained. Table 1 shows the physical properties of the polymer (A-2).

Production Example 3: Production of polyfarnesene (B-1) 241 g of cyclohexane as a solvent and 28.3 g of sec-butyllithium (10.5 mass% cyclohexane solution) as an initiator were charged in a pressure-resistant container purged with nitrogen and dried at 50 ° C. Then, 342 g of β-farnesene was added and polymerized for 1 hour. The obtained polymerization reaction liquid was treated with methanol, and the polymerization reaction liquid was washed with water. The polymerization reaction solution after washing was separated from water and dried at 70 ° C. for 12 hours to obtain liquid polyfarnesene (hereinafter also referred to as “polymer (B-1)”). Table 1 shows the physical properties of the polymer (B-1).

Production Example 4: Production of polyfarnesene (B-2) In a pressure-resistant container purged with nitrogen and dried, 304 g of cyclohexane as a solvent and 1.5 g of sec-butyllithium (10.5 mass% cyclohexane solution) as an initiator were charged at 50 ° C. Then, 302 g of β-farnesene was added and polymerized for 1 hour. The obtained polymerization reaction liquid was treated with methanol, and the polymerization reaction liquid was washed with water. The polymerization reaction solution after washing was separated from water and dried at 70 ° C. for 12 hours to obtain liquid polyfarnesene (hereinafter also referred to as “polymer (B-2)”). Table 1 shows the physical properties of the polymer (B-2).

Production Example 5 Production of Polyisoprene (X-1) Isoprene was anionically polymerized in n-hexane using n-butyllithium as an initiator to obtain a liquid polyisoprene having a number average molecular weight of 20,000. Table 1 shows the physical properties of polyisoprene (X-1).

Production Example 6: Production of polybutadiene (X-2) By subjecting butadiene to anionic polymerization in n-hexane using n-butyllithium as an initiator, liquid polybutadiene having a number average molecular weight of 9,000 was obtained. Table 1 shows the physical properties of polybutadiene (X-2).

Production Example 7 Production of Polybutadiene (X-3) Butadiene was anionically polymerized in n-hexane using n-butyllithium as an initiator to obtain a liquid polybutadiene having a number average molecular weight of 44,000. Table 1 shows the physical properties of polybutadiene (X-3).

 

<Examples 1 to 9>
Polymers (A-1), (A-2), (B-1), (B-2), (X-2) obtained in each production example, a polymerization initiator (C-1), The monomer (D) and the hindered amine compound (E) are charged into a stainless steel 300 mL container at a ratio shown in Table 2 and mixed at room temperature for 20 minutes using a stirring blade to obtain 200 g of a resin composition. Manufactured. The obtained resin composition was evaluated by the following method. The results are shown in Table 2.

<Comparative Examples 1 to 6>
Polymers (A-1), (A-2), (X-1) to (X-3) obtained in each production example, a polymerization initiator (C-1) and a monomer (D) A resin composition was produced and evaluated in the same manner as in Example 1 except that it was blended at the ratio shown in Table 3. The results are shown in Table 3.

<Evaluation method>
(1) Measurement of number average molecular weight and molecular weight distribution Using GPC-8020 manufactured by Tosoh Corporation, the concentration was adjusted to a concentration of sample / tetrahydrofuran = 5 mg / 10 mL.
The number average molecular weight (Mn) and the molecular weight distribution (Mw / Mn) were determined in terms of standard polystyrene equivalent molecular weight by GPC (gel permeation chromatography). The measuring apparatus and conditions are as follows.
・ Device: GPC device “GPC8020” manufactured by Tosoh Corporation
Separation column: “TSKgel G4000HXL” manufactured by Tosoh Corporation
・ Detector: “RI-8020” manufactured by Tosoh Corporation
・ Eluent: Tetrahydrofuran (Wako Pure Chemical Industries, Ltd.)
・ Eluent flow rate: 1.0 ml / min ・ Sample concentration: 5 mg / 10 ml
-Column temperature: 40 ° C

(2) Melt viscosity, glass transition temperature, and functional group equivalent Polymers (A-1), (A-2), (B-1), (B-2) and (X- The melt viscosities at 38 ° C. of the resin compositions obtained in 1) to (X-3) and in each Example and Comparative Example were measured with a Brookfield viscometer (manufactured by BROOKFIELD ENGINEERING LABS. INC.).

10 mg of the polymer obtained in Production Examples 1 to 7 was collected in an aluminum pan, and a thermogram was measured by a differential scanning calorimetry (DSC) under a temperature rising rate condition of 10 ° C./min. The peak top value of DDSC was obtained. The glass transition temperature was taken.

Using a ¹ H-NMR measuring apparatus (500 MHz) manufactured by JEOL Ltd., a ¹ H-NMR spectrum was measured at a concentration of sample / deuterated chloroform = 100 mg / 1 mL, 512 times of integration, and a measurement temperature of 50 ° C.
About the spectrum obtained by measuring the polymer (A), from the area ratio of the peak derived from the double bond of the methacryloyl group and the peak derived from the double bond of the polymer main chain, it corresponds to 1 equivalent of the methacryloyl group. The mass of the polymer, that is, the functional group equivalent was calculated.
The number of polymerizable functional groups per molecular chain was calculated from the number average molecular weight of the polymer (A) and the functional group equivalent determined by the above method.

(3) Appearance After injecting the resin compositions obtained in Examples and Comparative Examples into a mold having a length of 70 mm, a width of 70 mm, and a thickness of 0.5 mm, and covering the surface of the composition with a PET film having a thickness of 50 μm Using a UV irradiation device (manufactured by GS Yuasa Corporation, using HAK125L-F as a mercury lamp), the illuminance is set to 45 mW / cm ² and the conveyor speed is set to 0.25 m / min. / Cm ² UV was irradiated. This was repeated three times to obtain a cured product. After peeling the PET film from the cured product, the film was observed with the naked eye and the transparency was evaluated according to the following criteria.
<Evaluation criteria>
5: colorless and transparent 4: very slight coloring is observed, but transparent 3: slightly colored, but transparent 2: clear coloring is observed, but transparent 1: opaque

(4) Breaking strength and breaking elongation Breaking strength when a strip-like sample having a width of 6 mm and a length of 70 mm is punched from the cured product obtained in (3) and a tensile test is performed at a pulling speed of 50 mm / min. The breaking elongation was measured with an Instron tensile tester.

 

 

From Tables 2 and 3, the resin compositions of Examples 1 to 3 and Examples 6 and 7 are polyisoprene (A-1) and polyfarnesene (B-1 or B-) having a methacryloyl group which is a polymerizable functional group. 2), both of them have a lower viscosity than the comparative example 4 containing only the polyisoprene (A-1) having a methacryloyl group, and the elongation at break was improved without impairing the appearance. . In Examples 2, 3 and 6, the breaking strength was also improved as compared with Comparative Example 4. Furthermore, as shown in Example 8, even when other conjugated diene polymers were used in combination, a viscosity reducing effect and a cured film breaking elongation improving effect were similarly observed. Further, as is clear from the comparison between Example 9 and Comparative Example 6, also in the resin composition having a high monomer (D) content, the viscosity reducing effect, the breaking elongation and the breaking strength of the cured film are improved. The effect was seen.
Since the resin compositions of Examples 4 and 5 contain polyfarnesene (A-2) and polyfarnesene (B-1) having a methacryloyl group that is a polymerizable functional group in the molecule, they have a methacryloyl group. Compared with Comparative Example 5 containing only polyfarnesene (A-2), the viscosity, elongation at break and strength at break were improved.
On the other hand, in the resin compositions of Comparative Examples 1 to 3, polyisoprene (X-1) or polybutadiene (X-2 or X-3) was blended with polyisoprene (A-1) having a methacryloyl group in the molecule. Although it was a composition, the elongation at break was reduced as compared with Examples 1 to 3 blended with polyfarnesene.
Further, according to a comparison between Example 1 and Comparative Example 2, with polyfarnesene (B-1) and polybutadiene (X-2) having the same molecular weight, the use of polyfarnesene is superior in the effect of reducing the viscosity. It became clear.

Claims (16)

1. A polymer (A) containing a monomer unit (a1) derived from a conjugated diene compound and having a polymerizable functional group, a polymer containing a monomer unit (b1) derived from farnesene and having no polymerizable functional group A resin composition comprising a polymer (B) and a polymerization initiator (C) and having a mass ratio [(A) / (B)] of the polymer (A) to the polymer (B) of 0.01 to 100 .
2. The resin composition according to claim 1, further comprising 0.01 to 1,000 parts by mass of the monomer (D) with respect to 100 parts by mass in total of the polymer (A) and the polymer (B).
3. The resin composition according to claim 1 or 2, wherein the content of the polymerization initiator (C) in the total amount of the resin composition is 0.1 to 20% by mass.
4. The resin composition according to any one of claims 1 to 3, further comprising 0.01 to 10% by mass of the hindered amine compound (E) in the total amount of the resin composition.
5. The resin composition according to any one of claims 1 to 4, wherein the melt viscosity at 38 ° C of at least one of the polymer (A) and the polymer (B) is 0.1 to 3,000 Pa · s.
6. 6. The resin composition according to claim 1, wherein the polymer (B) has a number average molecular weight of 1,000 to 1,000,000.
7. 7. The resin composition according to claim 1, wherein the monomer unit constituting the polymer (B) consists only of the monomer unit (b1) derived from farnesene.
8. The monomer unit constituting the polymer (B) contains a monomer unit (b1) derived from farnesene and a monomer unit (b2) derived from a monomer other than farnesene. The resin composition in any one.
9. The resin composition according to claim 8, wherein the monomer unit (b2) is a monomer unit derived from a conjugated diene compound other than farnesene.
10. The resin composition according to claim 8, wherein the monomer unit (b2) is a monomer unit derived from an aromatic vinyl compound.
11. The resin composition according to any one of claims 1 to 10, wherein the monomer unit constituting the polymer (A) comprises only the monomer unit (a1) derived from a conjugated diene compound.
12. The monomer unit constituting the polymer (A) contains a monomer unit (a1) derived from a conjugated diene compound and a monomer unit (a2) derived from a monomer other than the conjugated diene compound. Item 11. The resin composition according to any one of Items 1 to 10.
13. The resin composition according to claim 11 or 12, wherein the conjugated diene compound as the monomer unit (a1) is at least one selected from farnesene, isoprene and butadiene.
14. The polymerizable functional group of the polymer (A) is at least one selected from a (meth) acryloyl group, an epoxy group, an oxetanyl group, a vinyl ether group, and an alkoxysilyl group, which may have a substituent. The resin composition according to any one of claims 1 to 13.
15. A cured product obtained by curing the resin composition according to any one of claims 1 to 14.
16. An optical pressure-sensitive adhesive containing the resin composition according to any one of claims 1 to 14.